Chain strech
 

When checking chain stretch and after you align the cam marks and look at the crank marks to determine strech if any what side of top dead center should the strech show. ATDC or BTDC? Have read all the threads but have found none that mention this. Thanks for any imput. 1990 350 SDL w/ 603 Engine.

Not familiar with yours . . . however I did a quick search and found these amoung many contributions addressing the subject. Hope these lead to the answer to your question.


http://www.peachparts.com/shopfor...ight=cam+timing

Here are the specifications for the valve timing events:
http://www.peachparts.com/shopfor...&threadid=64144

You will see who the contributors were.

I know nothing of this engine
But would not the crank set at tdc. cause the cam to be late to get to their mark if the chain had stretch???

So to have the cam at correct position the crank would have to turn more
with a worn chain and actually be ATDC.

What I am trying to say is a streched chain causes the cam to lag

Timing
 

Thanks for the imput. The treads that were posted would not come up. But the cam lag post puts it in perspective.

Crank will be ATDC. If BTDC, the cam is off a tooth and the pistons will be hitting the valves.

Peter